Preparation of polylactic acid-polylipoic acid nanospheres as drug targeting carriers

Polylactic acid-polylipoic acid nanospheres (PLA-PLIA-NS) were prepared, and their properties as drug targeting dosage forms were evaluated. A computer optimization technique was applied to obtain particles with nanometer order diameters and spherical shapes. Optimum preparative conditions involved the use of 2.4% hydroxypropyl cellulose (HPC), as a stabilizing agent, 24 min ultrasonication time, and 20% PLIA content. PLIA, containing a thiol group, was used for the conjugation of antibodies with the PLA-PLIA-NS surface. In this way, fairly spherical particles of PLA-PLIA-NS with a mean diameter of about 500 nm were obtained. The conjugation was investigated to determine targeting ability more precisely. Using rabbit antihuman IgG (Fab' fragment) antibodies, conjugation with PLA-PLIA-NS was accomplished by a disulphide binding reaction. The PLA-PLIA-NS-antibody conjugates were found to recognize IgG antigen bound to the surface of Sepharose beads.